@ombremad @schratze (Germany) yeah from what I recall here it's at most 2 days when they can't identify you at all (e.g. people who slash their fingerprints). most detained activists from protests are released by late night of the same day.
actual crime (Straftat) charges, if any, will come later (sometimes much later) by post with a court summons. and then there's a whole process where evidence must be shown and lawyers argue convincingly that you in particular broke laws.
of course you can at any point request to talk to a lawyer, and to call the EA if it's a public event. most people write the phone numbers on their skin with permanent marker or waterproof eye pencil, as the cops are known to deny access to your cellphone (and to try to rub off the written numbers, too). but theoretically they are required to find out your lawyer's phone number by name, so it pays off to memorise the full names of a couple criminal lawyers friendly to activism.